There are several types of known surgical fastener applying devices which comprise an actuator for removably receiving a fastener containing cartridge. One such device is shown in Hirsch et al. U.S. Pat. No. 3,275,211. In the Hirsch et al. device, a cartridge containing a plurality of surgical staples fits snugly into a cartridge holder element of the actuator. The cartridge holder element reciprocates linearly toward or away from an anvil portion of the actuator by operation of a first actuator control element (i.e., a rotating knob or wing nut). In particular, the tissue to be fastened is clamped between the cartridge and the anvil by reciprocating the cartridge holder element (and therefore the cartridge) toward the anvil. The staples are driven from the cartridge and part way through the clamped tissue by operation of a second actuator control element (i.e., a pivoting handle). The ends of the staple legs are crimped or clinched by contact with the anvil.
The Hirsch et al. device has many desirable features, but satisfactory operation of that device depends on accurate alignment between the cartridge and the anvil in order to assure that all of the staple legs enter the staple clinching pockets in the anvil for proper clinching by the anvil. Thus the cartridge must fit snugly in the cartridge holder element, and the cartridge holder element must be precisely aligned with the anvil, while at the same time being movable relative to the anvil and capable of resisting the large tissue clamping and staple clinching forces which tend to drive the staple holder and anvil apart.
Some of the requirements of the Hirsch et al. device are alleviated by devices of the type shown in Green U.S. Pat. No. 4,383,634. In the Green device the staple holder, anvil, and alignment pin are all connected together in a single disposable unit. In addition, the alignment pin operates automatically when the actuator is operated. The elements which provide the necessary precise alignment between the staple holder and anvil are also all confined to the cartridge assembly, thereby greatly simplifying and reducing the cost of the actuator. However, in the Green device, the staple holder and anvil are pivotally connected to one another (although limited translational motion of these elements is also possible). Some users prefer the purely linear reciprocation of the staple holder relative to the anvil which is characteristic of the Hirsch et al. device.
In view of the foregoing, it is an object of this invention to improve and simplify surgical fastener applying apparatus of the type described above.
It is a more particular object of this invention to provide surgical fastener applying apparatus which combines the relatively low cost construction and simplified operation of the above-mentioned Green device with the linear relative motion of the staple holder and anvil in the above-mentioned Hirsch et al. device.